Author: Danilo

Registering a RHEL System for Red Hat Support shows how to register a Red Hat Enterprise Linux system to get Red Hat features, such as support, software repositories, bug fixes, enhancements, etc. Red Hat provides access to software repositories through the Red Hat Content Delivery Network (CDN) in a subscription-based model. Software repositories provide regularly updated packages, including security patches, bug fixes, and enhancements. Customers with active subscriptions can access Red Hat content repositories to install new software packages and to stay up-to-date with the latest updates. In addition to software updates, an active subscription provides customers with technical resources such as Customer…

firewalld on RHEL 8 is the default firewall management service used to control network traffic and improve system security. It provides a flexible way to define rules, allowing administrators to manage incoming and outgoing connections based on different network requirements. Unlike directly managing low-level firewall rules, firewalld provides an abstraction layer based on zones, services, ports, and interfaces. This approach simplifies firewall administration while maintaining the flexibility required in enterprise Linux environments. In this article, we will explore the main concepts of firewalld on RHEL 8, including how zones work, how to check the firewall status, and how to configure…

Configuring network interfaces on RHEL 8 is an essential task for Linux administrators who need to manage connectivity in enterprise environments. Red Hat Enterprise Linux provides powerful tools such as nmcli and nmtui to create, modify, and troubleshoot network configurations. The NetworkManager service is responsible for dynamically managing network devices and connections on RHEL systems. Through command-line and interactive interfaces, administrators can configure wired, wireless, virtual, and advanced networking setups without manually editing configuration files. In this article, we will explore how to use nmcli and nmtui to configure network interfaces on RHEL 8, including DHCP configuration, static IPv4 settings,…

GRUB2 (GRand Unified Bootloader version 2) is the default boot loader on most Linux flavors. It resides in the Master Boot Record (BIOS systems) or the UEFI System Partition (UEFI systems) and is responsible for: How does GRUB2 work? Basically, we can pop up some GRUB2 stages: Stage 1: Installed in the MBR or EFI partition, this tiny stub locates the rest of GRUB2. Stage 1.5 (with BIOS only): Optional modules that allow GRUB2 to understand filesystems on /boot. Stage 2: Reads the configuration file (grub.cfg), displays the menu, and loads the selected kernel and initramfs: Configuration Files and Layout…

This article explains what shell scripting is and provides some examples of usage. We’re using Red Hat Enterprise Linux, but all commands work in any Linux flavor. First and foremost: What is Shell Scripting? In Linux, a shell script is simply a text file containing commands you would normally type in the terminal, but saved so they can be run together as a program. To run these commands, we need a command interpreter. The most used command interpreter is the bash (Bourne Again Shell). Example of a simple shell script: The first script line “#!/bin/bash” is known as a shebang…

Using “tar” on RHEL 8 shows how to use the “tar” command to perform backups and archives, with or without compression, and provides a lot of examples of usage. All the practical examples are shown using Red Hat Enterprise Linux; however, they work on any Linux flavor. First and foremost: What is “tar”? The command “tar” stands for “tape archive”.Originally used to back up data to tapes, but now commonly used for: A “.tar” file is just an archive, with no compression by default.A “.tar.gz” or “tgz” is a tar archive compressed with gzip.A “.tar.bz2”, “tbz”, or “tbz2” is a…